Vendor comparison · 2026
Semaglutide vendors: 14 compared on COAs and price
MetabolicAlso known as GLP-1 receptor agonist
Evidence tier
Regulator-reviewed human evidence
5 human trials · 1 review · approved counterpart
- Vendors carrying it
- 14
- 11 with a listed price
- Vendors with checkable COAs
- 7
- 7 publish any certificate
- Lots tested
- 9
- 8 naming a checkable lab
- Independent assays
- 0
- none on file yet
- Newest assay
- 25 Sept 2026
- oldest 24 Feb 2026
- Laboratories named
- 5
- most often ILS Laboratories
- Median label gap
- 8.3%
- 22% of lots within 5% of label
- Median purity
- 99.76%
- 8 of 9 lots at 99% or above
- Lowest price per mg
- $4.20
- peer median $6.50
- Publications located
- 5.3k
- researched since 2012
Source: PepIndex, an independent index of research-peptide vendors. No vendor can pay for a rank, every score is computed by a published formula, and every figure links to the document it was read from.
Hydro Research Peptides has the most checkable Semaglutide testing in this index: 2 lots assayed by ILS Laboratories, the newest on 8 Jul 2026. The lowest listed price is $4.20 per mg at Bench Grade Peptides, against a peer median of $6.50. 14 vendors carrying Semaglutide are compared below. 7 publish at least one certificate naming a checkable laboratory, 9 lot records are on file, and none is an independently commissioned assay. Figures are PepIndex's own: it is an independent index of research-peptide vendors, no vendor can pay for a rank, and each figure links to the certificate it was read from.
Every vendor carrying Semaglutide
| # | Vendor | Score here | Price / mg | Lots | Newest test | Laboratory | Mean purity | Label gap | Reports |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Amino ClubISO/IEC 17025Age-gated COAs | 90.198% | $5.00 (77%) | 0 | — | — | — | — | |
| 2 | Ascend ScienceISO/IEC 17025 | 88.994% | — | 1 / 1 | Kovera Labs and/or ILS Labs | 99.7% | 5.2% | ||
| 3 | Bench Grade Peptides | 87.789% | $4.20 (65%) | 1 / 1 | Freedom Diagnostics Testing | 99.9% | 17.4% | ||
| 4 | Northline LabsISO/IEC 17025 | 87.795% | $4.50 (69%) | 1 / 1 | ILS Laboratories | 99.2% | 1.2% | ||
| 5 | Hydro Research PeptidesISO/IEC 17025 | 83.289% | $5.00 (77%) | 2 / 3 | ILS Laboratories | 99.4% | 11.4% | ||
| 6 | Simple Peptide | 79.192% | — | 1 / 1 | Freedom Diagnostics Testing | 99.9% | 25.1% | ||
| 7 | Ascension Peptides | 78.989% | — | 1 / 1 | MZ Biolabs | 100.0% | 4.0% | ||
| 8 | Koi PeptidesAge-gated COAs | 74.992% | $7.00 (108%) | 0 | — | — | — | — | no reportVisit site |
| 9 | True Research Labs | 70.568% | $4.40 (68%) | 0 | — | — | — | — | no reportVisit site |
| 10 | Evo Labs Research | 69.287% | $7.50 (115%) | 0 | — | — | — | — | no reportVisit site |
| 11 | Good Science Bio | 67.571% | $6.50 (100%) | 0 | — | — | — | — | no reportVisit site |
| 12 | Prime PeptidesISO/IEC 17025 | 62.796% | $11.00 (169%) | 1 / 1 | Vanguard Laboratory | 99.0% | 10.2% | ||
| 13 | Improved Peptides | 58.887% | $9.20 (142%) | 0 | — | — | — | — | no reportVisit site |
| 14 | GenX Peptides | 52.869% | $11.80 (182%) | 0 | — | — | — | — | no reportVisit site |
Independent assays
No independently commissioned assay of Semaglutide is on file. All 9 records below were published by the vendor that sells the product, naming the laboratory shown. PepIndex does not yet commission its own assays, so nothing on this page establishes what is in a vial beyond the vendor’s own certificate. A record moves into this section the moment an assay commissioned by anyone other than the seller is indexed.
What the certificates show
8 of 9 lots at 99% or above; median 99.76%.
| Range | lots |
|---|---|
| <95% | 0 |
| 95–97% | 0 |
| 97–98% | 0 |
| 98–99% | 1 |
| 99–99.5% | 2 |
| ≥99.5% | 6 |
22% of lots within 5% of the labelled mass; median gap 8.3%.
| Range | lots |
|---|---|
| ≤2% | 1 |
| 2–5% | 1 |
| 5–10% | 3 |
| 10–20% | 3 |
| >20% | 1 |
11 vendors, $4.20 to $11.80; median $6.50.
| Range | vendors |
|---|---|
| $4.00–$6.00 | 5 |
| $6.00–$8.00 | 3 |
| $8.00–$10.00 | 1 |
| $10.00–$12.00 | 2 |
Purity and mass are read from each certificate as published; the label gap is |labeled − assayed| ÷ labeled. Every value behind these bars is in the certificate table below.
Laboratories used
| Laboratory | Lots | Vendors | Share | Verify |
|---|---|---|---|---|
| ILS LaboratoriesUS | 3 | 2 | 33% | Public lookup |
| Freedom Diagnostics TestingUS | 2 | 2 | 22% | Public lookup |
| Kovera Labs and/or ILS Labs | 1 | 1 | 11% | No public lookup found |
| MZ BiolabsUS | 1 | 1 | 11% | No public lookup found |
| Vanguard LaboratoryUS | 1 | 1 | 11% | No public lookup found |
1 further record namesno checkable laboratory (a placeholder, a signature line or the vendor’s own name). It is listed in the certificate table but not counted as third-party testing.
Every certificate record
Score breakdown
The score has two halves: the research base — how long the compound has been studied and how much has been published — and the quality of the evidence the market produces for it, aggregated across every vendor that carries it: assayed purity, lot-to-lot consistency, readable third-party certificates and those vendors’ review record. It measures the evidence base, not the merits or safety of the substance.
Studied since 2012 — 14 years of published research
How long the compound has been studied. Fifteen years or more of published literature earns full marks; a newer compound earns less.
5,342 publications indexed in PubMed
The volume of published literature located. Full marks at fifty or more publications.
Mean assayed purity 99.6% across 9 certificates
Average assayed purity on the certificates published by vendors that carry this compound. Full marks at 99.5%+, nothing at 95% or below.
±0.43 pts purity across lots, mean label deviation 10.8%
How tightly assayed purity and labeled-versus-actual mass hold across different lots. Rewards reproducible manufacturing.
14 of 14 listing vendors publish an accessible certificate policy
Whether the vendors carrying this compound publish per-lot certificates anyone can read without an account.
8 of 9 certificates from a recognised independent lab
Share of certificates issued by a recognised third-party testing lab rather than an unnamed or self-named one.
What is Semaglutide?
A GLP-1 receptor agonist peptide. Semaglutide is an approved prescription medicine in several jurisdictions under brand names held by its originator; material listed by the vendors in this index is sold as research-grade powder and is not the approved pharmaceutical product.
Studied in published research for type 2 diabetes and obesity / weight management.
Regulatory status
Approved as a prescription medicine in several jurisdictions. Research-grade material listed by indexed vendors is labeled for laboratory research use only and is not the approved product.
What the research examines
The areas of published research this compound appears in. These describe what the literature has studied — never a claim of benefit, effect or suitability for any use.
Published research
An extensive published clinical literature exists for the approved pharmaceutical product. That literature concerns the approved product under medical supervision and does not extend to research-grade material of unverified identity or purity. This index records what vendors publish about the material they sell and nothing more.
- Safety of Semaglutide — Frontiers in endocrinology (2021)
Peer-reviewed article indexed in PubMed, published in Frontiers in endocrinology (2021).
- Semaglutide for the treatment of obesity — Trends in cardiovascular medicine (2023)
Peer-reviewed article indexed in PubMed, published in Trends in cardiovascular medicine (2023).
- Semaglutide 2·4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2): a randomised, double-blind, double-dummy, placebo-controlled, phase 3 trial — Lancet (London, England) (2021)
Peer-reviewed article indexed in PubMed, published in Lancet (London, England) (2021).
- Efficacy and Safety of Semaglutide for Weight Loss in Obesity Without Diabetes: A Systematic Review and Meta-Analysis — Journal of the ASEAN Federation of Endocrine Societies (2022)
Peer-reviewed article indexed in PubMed, published in Journal of the ASEAN Federation of Endocrine Societies (2022).
- Semaglutide lowers body weight in rodents via distributed neural pathways — JCI insight (2020)
Peer-reviewed article indexed in PubMed, published in JCI insight (2020).
- Wegovy (semaglutide): a new weight loss drug for chronic weight management — Journal of investigative medicine : the official publication of the American Federation for Clinical Research (2022)
Peer-reviewed article indexed in PubMed, published in Journal of investigative medicine : the official publication of the American Federation for Clinical Research (2022).
- Clinical Pharmacokinetics of Semaglutide: A Systematic Review — Drug design, development and therapy (2024)
Peer-reviewed article indexed in PubMed, published in Drug design, development and therapy (2024).
- Risk of Nonarteritic Anterior Ischemic Optic Neuropathy in Patients Prescribed Semaglutide — JAMA ophthalmology (2024)
Peer-reviewed article indexed in PubMed, published in JAMA ophthalmology (2024).
Indexed studies6 human-evidence of 6
- Randomised controlled trials of semaglutide, the approved medicine — Human — controlled trial
An extensive randomised controlled trial literature exists for the approved pharmaceutical product, conducted under medical supervision with a product of verified identity and purity. It is evidence about that product, not about research-grade material of unverified content.
- Meta-analyses of GLP-1 receptor agonist trials — Meta-analysis
Pooled analyses of trials of approved GLP-1 receptor agonist products. Meta-analytic findings inherit the population and product of the trials they pool, and do not transfer to material obtained outside that supply chain.
- Once-Weekly Semaglutide in Adults with Overweight or Obesity — Human — controlled trial, 2021
Obesity is a global health challenge with few pharmacologic options. Whether adults with obesity can achieve weight loss with once-weekly semaglutide at a dose of 2.4 mg as an adjunct to lifestyle intervention has not been confirmed. In this double-blind trial, we enrolled 1961 adults with a body-mass index (the weight in kilograms divided by the square of the height in meters) of 30 or greater (≥27 in persons with ≥1 weight-related coexisting condition), who di…
- Tirzepatide as Compared with Semaglutide for the Treatment of Obesity — Human — controlled trial, 2025
Tirzepatide and semaglutide are highly effective medications for obesity management. The efficacy and safety of tirzepatide as compared with semaglutide in adults with obesity but without type 2 diabetes is unknown. In this phase 3b, open-label, controlled trial, adult participants with obesity but without type 2 diabetes were randomly assigned in a 1:1 ratio to receive the maximum tolerated dose of tirzepatide (10 mg or 15 mg) or the maximum tolerated dose of semaglutide (1.…
- Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension — Human — controlled trial, 2022
To explore changes in body weight and cardiometabolic risk factors after treatment withdrawal in the STEP 1 trial extension. STEP 1 (NCT03548935) randomized 1961 adults with a body mass index ≥ 30 kg/m2 (or ≥ 27 kg/m2 with ≥ 1 weight-related co-morbidity) without diabetes to 68 weeks of once-weekly subcutaneous semaglutide 2.4 mg (including 16 weeks of dose escalation) or placebo, as an adjunct to life…
- Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity: The STEP 4 Randomized Clinical Trial — Human — controlled trial, 2021
The effect of continuing vs withdrawing treatment with semaglutide, a glucagon-like peptide 1 receptor agonist, on weight loss maintenance in people with overweight or obesity is unknown. To compare continued once-weekly treatment with subcutaneous semaglutide, 2.4 mg, with switch to placebo for weight maintenance (both with lifestyle intervention) in adults with overweight or obesity after a 20-week run-in with subcutaneous semaglutide titrated to 2.4 mg weekly. Randomized, …
Evidence digest
What the research on semaglutide actually shows
Semaglutide has one of the strongest human evidence bases of any compound in this index — and none of it attaches to research-grade powder. The randomised controlled trials were run on an approved pharmaceutical product of verified identity and purity, administered under medical supervision. Material sold for research use is not that product, and the trial evidence does not transfer to it. What a research-grade vial contains is established only by its certificate of analysis, if one exists.
4 things the literature does not establish →
PepIndex describes what literature exists. We do not interpret it, assess clinical significance, or publish quantities, protocols or instructions for use.